Uniformity of Powder Coating

[DonMountain]

I have been purchasing some 9mm 115 grain powder coated lead projectiles to begin loading my 9mm Luger pistol. Now that I have worked out a load that works well, I purchased a cheapy 125 grain LEE mold to try out casting for the 9mm. Looking at the purchased powder coated projectiles, it seems that the powder coating is very uniform. What affect does powder coating have on bullet balance and how do you coat your projectiles to attain this uniformity?

[earlmck]

I don't know about the electrostatic spray gun technique: I use either shake 'n bake or vibratory tumbler technique and then I dump coated boolits in a plastic spaghetti colander I got from the wife and shake and sift until all loose powder is gone. After baking I have a uniform but very thin PC coating which works well but is not as pretty as many of the PC guys on here produce or as pretty as the commercial fellows produce. If I leave enough for "pretty" I get non-uniform, so I stay with splotchy-looking but uniform. Other folks on here can no doubt steer you to better strategies.

[Smoke4320]

Powdercoating weighs next to nothing .. uneven application has little to no effect
when I started PCing we took trays and glued hex nuts to them the covered with non stick aluminum foil
Stuck RIFLE bullets nose down thru the foil.. Bullets would end up in all directions . sprayed them, many would then have a pretty good ring of powder around the circumference near the ojive .. They shot and grouped accurately as long as I did my part

[mdi]

I started dry tumbling my bullets with powder only in a white plastic tub. I also put a container of powder and bullets in my rotary tumbler (I stuffed rags around the container to keep it from tumbling). I picked the tumbled bullets out of the container with long tweezers after about 15 minutes and sat them on a sheet of non stick aluminum foil, base down then cooked them. I got good results and an even coat when cooking for 20 minutes @ 300 degrees (IIRC the temp.). Worked for about 1,000 then I purchased an electro-static set up from HF. See the Coatings and Alternative sub forum for more, better info....

I loaded my PCed bullets with the same methods and used the same reloading data as my cast lead bullets. Basic performance, accuracy, function, etc. was the same as with my nekkid cast lead bullets...

[popper]

First question - PC or HiTek coated that you purchased (MBC does HiTek). They are different. Neither coating will effect your pistol accuracy! PC may effect your loading procedure, seating depth, etc.
I recently shot 168gr ESPC (2400 fps) @ 200 and got near MOA in a field with portable bench. Buddy shot 7 rnds before me (same rifle & ammo) and did pretty good too.
I recently weighed the same boolit naked and DTPC'd - 0.2gr difference (accuracy of my digital scale). If you move all the weight to one side (0.0001 imbalance) effectively moves weight 0.00002 off axial CG, not enough to cause any imbalance at any (reasonable) rotational speed.
That said, displacement of alloy due to the variation in coating thickness will increase imbalance but still NOT enough to make a difference.
I only cast for 30 cal rifle but larger cal will be the same. Smaller (223) should hold the same as surface area is proportional to size.
Which brings up the weight sampling idea. A while back Larry & Tim had a discussion about weight culling boolits aka, the 'bell' curve. IMHO they finally agreed that the weight difference was due to as cast diameter and fillout, not 'voids' and impurities (yes they are possible but not probable and difficult to find by weight) . To do it right, you must sort by diameter and then weight. Then cull the outliers from BOTH sortings.

[gwpercle]

Uneven powder coating on boolits affecting balance....Splitting hairs ain't ya Boss ?
I wouldn't worry about it unless you're shooting for big money .
Gary

[Panman213]

Don, if I understand correctly, your looking at possibly coating some 9mm. My quess is you will not notice a difference in accuracy from that of store bought stuff. I shoot PC'd boolits from many pistols and revolvers and even some pistol cal. carbines and I find the accuracy to be very good with no leading. Size your boolits correctly to YOUR gun and it will perform as well as any commercial stuff.

[OS OK]

I haven't seen one post here where someone tried to prove that 'off axis' weight distribution does or doesn't make any difference...I can't imagine how it does not in rifle at distance...therefore all this commentary, including mine is 'subjective'.

If you want to satisfy the question in your mind, change your process to do the best you can. IE. cast, size, PC and stand on end, size, load. There are even further refinements in the PC stage where 'tapping off of extra PC' is done and at this point you are tweezering them, that's a trigger for a lot of folks here...if you have a tendency to be OCD like me and a few others...this can become another rabbit hole for Ya!

[bangerjim]

If you are loading for 0.0005 MOA (!!) then PC may cause you some problems. I have found the coating has little effect on balance. I much prefer the ESPC method but also use the BBDT (help develop with others on here) method too. But ESPC is a more accurate coating, no heavy build-ups, no divots from tweezers or fingers, and works for my needs. Some don't care what their rounds look like, I do. But BBDT is very doable ( for most, anyway!) and very shootable

[popper]

OSOK - this has been an ongoing question by OPs here. The answer is NOT a problem. Myself, Bama, Avenger & others are proving it. Last I checked, money boys on CBA don't allow coatings in competition. If you are in the Money game, PC is the least of your worries. Same with weight sorting, unless you are in high competition, makes NO difference. Too many other factors that DO matter. For HV rifle, I'm finding that any boolit that can shoot good (I'm not that good a shot) the quality GC and BEST installation makes more difference than anything. Cast (proper alloy & load), weigh sort and slam that home made check on them - groups double. Flame away.

[marek313]

I powder coat all my boolits but I'm probably more anal then necessary because i still stand up all my projectiles on a sheet and make sure they are all evenly covered. I like casting and reloading so I dont mind watching TV while I slowly PC everything.

I would say as long as they are covered and dont have bare spots you should be ok and it wont affect accuracy much. Anything beyond that is just work pride if you ask me.

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[FredBuddy]

DonM:

You want uniform coating with the tumble method, try Smokes clear.

Beats anything.

[DonMountain]

I powder coat all my boolits but I'm probably more anal then necessary because i still stand up all my projectiles on a sheet and make sure they are all evenly covered. I like casting and reloading so I dont mind watching TV while I slowly PC everything.

I would say as long as they are covered and dont have bare spots you should be ok and it wont affect accuracy much. Anything beyond that is just work pride if you ask me.

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Wow! These really look good just like the commercially made ones. So, where is the hidden forum of instructions on powder coating and where to purchase supplies? I want to try this.

[DonMountain]

If you are loading for 0.0005 MOA (!!) then PC may cause you some problems. I have found the coating has little effect on balance. I much prefer the ESPC method but also use the BBDT (help develop with others on here) method too. But ESPC is a more accurate coating, no heavy build-ups, no divots from tweezers or fingers, and works for my needs. Some don't care what their rounds look like, I do. But BBDT is very doable ( for most, anyway!) and very shootable

So, what do the terms "ESPC" and "BBDT" mean? I assume the "PC" part is Powder Coat? But what is the rest?

[Gamsek]

https://www.mp-molds.com/tips-tricks/83-powder-coating-lead-bullets-dry-tumble-dt-method

For start, try with this. Just one way to skin the cat. Few quick tips for “shake and bake” aka “dry tumble” (DT) method.

And yes, Banger Jim, OS OK, popper, Dragonheart and few others developed this method. I learned from them right here. See also coatings and alternatives for more info.

Good luck!

[Bama]

Powdercoating weighs next to nothing .. uneven application has little to no effect
when I started PCing we took trays and glued hex nuts to them the covered with non stick aluminum foil
Stuck RIFLE bullets nose down thru the foil.. Bullets would end up in all directions . sprayed them, many would then have a pretty good ring of powder around the circumference near the ojive .. They shot and grouped accurately as long as I did my part

ALSO you are only looking at the difference in density between pc and lead that can effect the balance.

[rsrocket1]

So, what do the terms "ESPC" and "BBDT" mean? I assume the "PC" part is Powder Coat? But what is the rest?

ESPC = Electrostatic (Spray) Powder Coating - using a charged spray gun like the Harbor Freight spray gun (https://www.harborfreight.com/10-30-psi-powder-coating-system-94244.html) to spray charged powder onto the lead bullets.
Advantages: very uniform coating, works with many more powders than dry tumbling
Disadvantages: More costly to buy the equipment, overspray of powder (can be reused but might not be as good as fresh powder), must stand up the bullets and the bullets must make electrical contact with what they are standing on while spraying

BBDT: Shaking bullets and airsoft BB's in a plastic container. Powder making and breaking contact with the lead generates static electricity which causes the powder to stick to the lead.
Advantages: Costs almost nothing to start ($5-$12/# of powder and you need about 1/2 teaspoon per hundred bullets) + some airsoft BB's (opaque black are the best; use to help separate bullets from each other) + #5 plastic container (Tupperware or Cool Whip/Margarine container)
Disadvantages: More finicky than ESPC especially in humid conditions, touching bullets can rub powder off (although I use nitrile gloves to pick up the bullets and roll the bullets between my index finger and thumb and it makes the coating better)

Both need an oven to cure the powder. You can use a cheap toaster oven to bake them at 350 for 20-30 minutes. My 2 ovens cost me less than $3 each at the Goodwill Outlet disposal store and they hold the temperature very constant.

[Walter Laich]

I started with the spray gun and didn't like overspray (did a number of changes but still not what I wanted

went to BBDT with AS BBs and picked them out with tweezers--labor intensive to say the least

now BBDT with AS BBs, dump in colander to get rid of excess powder and BBs and dump on metal tray. Bake

There are a few marks on bullets but not enough to cause leading. I got over my need for perfect looking bullets when I found I can cast 16-18 lbs of lead into bullets, PC them and size them in 2 hours total.

[Taterhead]

Where I've noticed uneven powder coating causing a problem is in the area where bearing surface transitions to nose/ogive. A thick spot can affect chambering, especially on auto-loaders. I like the coatings to be even. I do tweeze and give a little tap on the side of the plastic container to dump excess powder. That makes an very even coat with very little flashing.

Here are a few of mine. The 45 on the left is HF Red. The rest are powders from Smoke4320.

https://s20.postimg.org/4frelzb71/20170425_210338.jpg

[OS OK]

Outstanding work there Tater...glad to see someone taking pride in their work. The results speak for themselves.

Question...who makes the mold for that pink buttonhead FWC? Or...is it called something else?

[Taterhead]

Outstanding work there Tater...glad to see someone taking pride in their work. The results speak for themselves.

Question...who makes the mold for that pink buttonhead FWC? Or...is it called something else?

OS OK, that is an NOE clone of the 358432. This one is the 160 gr version (casts 168). NOE calls it the "360-160-WC 360432". If I recall correctly, this one was an offshoot of a group buy pulled together at NOE, and it is now part of the catalogue.

http://noebulletmolds.com/NV/index.php?cPath=35_298&osCsid=ujbcvlnfg007to0g1g62se9qb6

I believe that there was a 148 gr version of the 358432.